With respect to color photographic materials, the materials are exposed to light, and then subjected to color development, thereby allowing oxidized color-developing agents to react with couplers to form images.
The color development is achieved by immersing the exposed photographic materials in aqueous alkali solutions (developing solutions) in which the color-developing agents are dissolved. However, many problems are encountered, such as easy deterioration of the developing solutions and waste liquid treatment of the spent developing solutions.
As a method for solving these problems, a method of allowing a hydrophilic colloid to contain an aromatic primary amine developing agent or a precursor thereof is proposed. Further, a method of allowing a hydrophilic colloid to contain a sulfonyl hydrazine type developing agent is also proposed. Examples of such methods include methods described in JP-B-58-14671 (the term "JP-B" as used herein means an "examined Japanese patent publication"), and methods described in EP 545,491 A1 and EP 565,165 A1.
However, these methods also suffer from the problem of insufficient color generation in development or pose a problem in storage stability.
Further, in the field of silver halide photographic materials, the so-called color diffusion transfer process in which diffusible dyes are formed imagewise and fixed to image receiving materials, thereby forming color images is a known art. With respect to this process, many proposals have been made. In this process, compounds obtained by making previously colored image formation dyes (preformed dyes) diffusion-resistant (hereinafter referred to as "coloring materials) are generally used. The addition of the coloring materials to layers having silver halide emulsions causes an undesirable reduction in sensitivity to exposure because of the filter effect due to dye portions. As methods for improving these disadvantages, so-called coupling systems in which dye formation is carried out by the coupling reaction of oxidation products of developing agents with couplers are proposed in U.S. Pat. No. 4,469,773 and JP-B-63-36487. However, with regard to the color-developing agents described in these, the storage stability is difficult to be compatible with the activity of the coupling reaction, or it is difficult to make both the color-developing agents and the couplers diffusion-resistant.
For solving the problems described above, novel color-developing agents are proposed in JP-A-08-286340 (the term "JP-A" as used herein means an "unexamined published Japanese patent application") and JP-A-09-152705. However, in combinations of the color-developing agents and couplers described in these, the color generation of yellow images is insufficient yet, or a problem arises with regard to the hue or color image stability of the yellow images formed.